Nah, you can buy dry ice commercially for about $1/kg in many places, it's used for shows, parties and food refrigeration. ln2 is only a little harder to obtain

Nah, you can buy dry ice commercially for about $1/kg in many places, it's used for shows, parties and food refrigeration. ln2 is only a little harder to obtain, but there are companies which will lease dewars and fill them with LN2. It's not like walmart level, but you can get them in bigger cities.